Galaxy S4 digitizer replacement: Intermittent touch detection problem

I replaced the entire LCD assembly including digitizer and glass after my GS4 got smashed. I must have done 90% of it right because it works flawlessly most of the time. Sometimes, however, the touch screen just stops working. Won't respond at all. In my frustration, I managed to find a curious workaround: I must press hard on the top left corner where the digitizer connects to the motherboard, then it works flawlessly again. I find this odd because if the problem was the connector, then there should be display issues as well, but there isn't. Just the touch problem. Does anyone know what this could be? Do I need to put adhesive somewhere or is there another connector I may have possibly missed during reassembly?

That's a good questions. You might want to retrace your steps and see if anything on the digitzier/motherboard appears to be missing or not well connected. By pressing that corner it seems as though there is a bad connection. Aside from that, I have no idea what the issue can be.